A known stator structure is disclosed in JP2009-89456A (hereinafter referred to as Patent reference 1), which aims at improving a performance of cooling a stator coil including split cores. According to the stator structure described in the Patent reference 1, a bus bar is connected to a resin-molded coil end portion, and cooling oil is sprayed at the bus bar for cooling the coil end portion.
However, the stator structure disclosed in the Patent reference 1 is for cooling the bus bar connected to the coil end portion, and thus a local cooling is applied to the coil end portion and an entire stator coil is not sufficiently cooled.
A need thus exists for a three-phase rotary electrical machine which is not susceptible to the drawback mentioned above.